//导入express包
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');

//导入路由路径
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var empRouter = require('./routes/emp');

var app = express();

//中间件
app.use(logger('dev'));

//处理前端发过来的请求格式
app.use(express.json());//请求JSON格式
app.use(express.urlencoded({ extended: false }));//处理x-wwwww-form-urlencoded格式

//中间件
app.use(cookieParser());

//动态配置静态资源
app.use(express.static(path.join(__dirname, 'public')));

//express解决跨域问题
app.all("*", function (req, res, next){ 
//设置允许跨域的域名，*代表允许任意域名跨域
res.header("Access-Control-Allow-origin","*");
//允许的header类型
res. header("Access-Control-Allow-Headers","content-type");
//跨域允许的请求方式
res.header("Access-Control-Allow-Methods","DELETE,PUT,POST,GET,OPTIONS"); 
if (req.method.toLowerCase()=="options"){ 
    res.send(200);//让options尝试请求快速结束
}else { 
    next();
    }
});



//使用路由
app.use('/', indexRouter);
app.use('/users', usersRouter);
app.use('/emps', empsRouter);

module.exports = app;
